From amongest the following alcohols, the one that would react
fastest with conc. HCl and anhydrous `ZnCl_(2)` is

Options

A. 1-Butanol
B. 2-Butanol
C. 2-Methypropan-2-ol
D. 2-Methylpropanol

Answer

To determine which alcohol reacts fastest with concentrated HCl and anhydrous ZnCl₂, we need to analyze the structure of the given alcohols and their classifications as primary, secondary, or tertiary alcohols. The reactivity order for alcohols when reacting with these reagents is tertiary > secondary > primary.

### Step-by-Step Solution:

1. **Identify the Types of Alcohols**:
- **1-Butanol (CH₃CH₂CH₂CH₂OH)**: This is a primary alcohol (1°) because the hydroxyl group (-OH) is attached to a carbon that is connected to only one other carbon.
- **2-Butanol (CH₃CH(OH)CH₂CH₃)**: This is a secondary alcohol (2°) because the hydroxyl group is attached to a carbon that is connected to two other carbons.
- **2-Methylpropane-2-ol (tert-butanol, (CH₃)₃COH)**: This is a tertiary alcohol (3°) because the hydroxyl group is attached to a carbon that is connected to three other carbons.
- **2-Methylpropanol (CH₃C(OH)CH₂CH₃)**: This is also a secondary alcohol (2°) because the hydroxyl group is attached to a carbon connected to two other carbons.

2. **Determine Reactivity**:
- The reactivity of alcohols with concentrated HCl and ZnCl₂ follows the order:
- Tertiary alcohols react the fastest.
- Secondary alcohols react slower than tertiary but faster than primary.
- Primary alcohols react the slowest.

3. **Conclusion**:
- Among the listed alcohols, **2-Methylpropane-2-ol (tert-butanol)** is the only tertiary alcohol. Therefore, it will react the fastest with concentrated HCl and anhydrous ZnCl₂.

### Final Answer:
The alcohol that would react fastest with concentrated HCl and anhydrous ZnCl₂ is **2-Methylpropane-2-ol (tert-butanol)**.

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